Going to, not should. Assume that all the "too big to steal" stuff falls through, and they really do say "Kamala got 150 million votes. We are going to swear her in. What are you going to do about it plebs?"
No wishful thinking about not pulling off another Steal, or fantasies about a million patriots marching on Washington or any of the usual PDW hopium. Not what should happen, what's your honest prediction of what actually will happen if they pull it off?
Any time frame you choose; the night of, the next day, the rest of November, in January, a year later, etc. An honest no shit cold assessment of the most likely real outcomes.
In a military operation order, there's two sections that deal with Enemy's Most Likely Course Of Action and Enemy's Most Dangerous Course of Action. Only fools only plan for a victory. Let's put the hope and optimism on the shelf for now, put our pragmatism hats on and actually consider outcomes from a falsified Trump defeat next month.
I don't think an actual civil war will immediately happen unless Trump gets killed. More likely a soft Balkanization will happen, where red states will start refusing to work with or obey the federal government. It'll be very politically popular to tell Kamala's administration to pound sand, so that'll happen a lot. A flashpoint will be when Texas starts physically and violently enforcing its border against the orders of the feds, and if the feds decide to come in and force the border open then that might kick off civil war. No idea what happens after that.
If we do have a civil war, it probably won't be noticeable at first because it won't be like our first civil war where we had two distinct nations fighting it out. It'll be an European style civil war where it's mostly guerilla and terror tactics.
So basically what happened in the summer of love 2020..
That's the thing, assuming we have a civil war, that probably will be included in the history books.
Riots happen with some regularity, and they are mostly ignored by history books as far as I know.